JP2003321538A - Polyester resin and film made thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyester resin giving films, fibers and molded articles such as bottles having excellent surface appearance while suppressing the problems in the forming of films, fibers, etc., such as the breakage, the yarn breakage and the deposition of decomposed resin, and provide a film composed of the resin. <P>SOLUTION: The polyester is produced by the polycondensation of a dicarboxylic acid component composed mainly of terephthalic acid or its ester- forming derivative with a diol component composed mainly of ethylene glycol after esterification reaction or transesterification reaction. The polyester resin and the film made of the polyester resin contains the number of foreign material particles having a maximum diameter of ≥1 μm is ≤20/0.01 mm<SP>3</SP>. The invention further provides a film made of the polyester resin. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention reduces the number of particles of different substances contained, and in particular, causes problems in molding such as breakage and yarn breakage in the formation of films and fibers, and the formation of eye crevices. The present invention relates to a polyester resin capable of obtaining a film or fiber having excellent surface appearance and a molded article such as a bottle, and a film made of the same.

[0002]

2. Description of the Related Art Conventionally, polyester resins such as polyethylene terephthalate resins are excellent in mechanical strength, chemical stability, gas barrier property, aroma retaining property, hygiene property, and the like.
Since it is relatively inexpensive and lightweight, it is widely used as films, fibers, bottles, and the like. On the other hand, in recent years, along with high-speed molding, molding problems such as film breakage, fiber yarn breakage, and occurrence of eye blemishes have become apparent, and various products have higher precision, higher speed, and higher quality. When the feeling is required, the surface appearance of films, fibers, bottles, etc. is inferior, the image is disturbed as a video tape, the image becomes difficult to see due to light scattering as the surface layer of the liquid crystal screen, or the condenser film As a result, various problems such as dielectric breakdown have been pointed out, and it is considered that these are caused by particles of different substances such as catalyst residues contained in the resin.

On the other hand, a polyester resin intended to reduce the number of particles of different substances such as catalyst residues contained therein has been proposed (for example, JP-A-8-188704 and JP-A-2000-256453). (See the bulletin, etc.)
According to the study by the present inventors, the reduction of the number of particles of different substances is not sufficient to solve the above-mentioned problems, and the polycondensation property, the formation of by-products, and the In terms of the color tone of the resin used, it has not been possible to sufficiently satisfy the market demand.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned prior art, and has problems in molding such as breakage and yarn breakage in forming a film, a fiber, etc. It is an object of the present invention to provide a polyester resin which is capable of obtaining a film or fiber that is suppressed and has an excellent surface appearance, and a molded product such as a bottle, and a film made of the same.

[0005]

Means for Solving the Problems In the present invention, as a result of intensive studies to solve the above problems, a polyester resin containing a very small number of particles of different substances is found as compared with conventionally known ones, and polycondensation is performed. By specifying the type and amount of phosphorus compounds that are sometimes present, and the amount and order of addition of various metal compounds such as antimony and titanium, there is no problem in polycondensation, formation of by-products, and color tone. It was found that a polyester resin having an extremely small number of particles of different substances was obtained, and the present invention has been reached. That is, the present invention is directed to a dicarboxylic acid component containing terephthalic acid or an ester-forming derivative thereof as a main component, and ethylene. A polyester resin obtained by polycondensation of a glycol-based diol component and an esterification reaction or transesterification reaction, Polyester resin Number of maximum diameter 1μm or more heterologous material particles to be perforated is 20 /0.01Mm ³ below, and consists of the polyester resin film, and the gist.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The polyester resin of the present invention comprises a dicarboxylic acid component containing terephthalic acid or an ester-forming derivative thereof as a main component and a diol component containing ethylene glycol as a main component in an esterification reaction or transesterification. It is obtained by polycondensation through a reaction.

Here, examples of the ester-forming derivative of terephthalic acid include alkyl esters having about 1 to 4 carbon atoms, and halides. Examples of dicarboxylic acid components other than terephthalic acid or its ester-forming derivative include phthalic acid, isophthalic acid, dibromoisophthalic acid, sodium sulfoisophthalate,
Phenylenedioxydicarboxylic acid, 4,4′-diphenyldicarboxylic acid, 4,4′-diphenyletherdicarboxylic acid, 4,4′-diphenylketonedicarboxylic acid,
4,4'-diphenoxyethanedicarboxylic acid, 4,4 '
-Aromatic dicarboxylic acids such as diphenyl sulfone dicarboxylic acid and 2,6-naphthalenedicarboxylic acid, alicyclic dicarboxylic acids such as hexahydroterephthalic acid and hexahydroisophthalic acid, and succinic acid, glutaric acid, adipic acid and pimelic acid , Suberic acid, azelaic acid, sebacic acid, undecadicarboxylic acid, dodecadicarboxylic acid, and other aliphatic dicarboxylic acids, and alkyl esters having about 1 to 4 carbon atoms, and halides thereof.

Examples of the diol component other than ethylene glycol include diethylene glycol which is a by-product in the reaction system. Other diol components include, for example,
Trimethylene glycol, tetramethylene glycol,
Aliphatic diols such as pentamethylene glycol, hexamethylene glycol, octamethylene glycol, decamethylene glycol, neopentyl glycol, 2-ethyl-2-butyl-1,3-propanediol, polyethylene glycol, polytetramethylene ether glycol, 1 , 2-Cyclohexanediol, 1,4-
Cyclohexanediol, 1,1-cyclohexanedimethylol, 1,4-cyclohexanedimethylol, 2,
Alicyclic diols such as 5-norbornane dimethylol, and xylylene glycol, 4,4'-dihydroxybiphenyl, 2,2-bis (4'-hydroxyphenyl)
Aromatic diols such as propane, 2,2-bis (4′-β-hydroxyethoxyphenyl) propane, bis (4-hydroxyphenyl) sulfone, bis (4-β-hydroxyethoxyphenyl) sulfonic acid, and 2, Two
-Ethylene oxide adduct or propylene oxide adduct of bis (4'-hydroxyphenyl) propane,
Etc.

Further, as a copolymerization component other than the above-mentioned diol component and dicarboxylic acid component, for example, glycolic acid,
Hydroxycarboxylic acids and alkoxycarboxylic acids such as p-hydroxybenzoic acid and p-β-hydroxyethoxybenzoic acid, and stearyl alcohol, heneicosanol, octacosanol, benzyl alcohol, stearic acid, behenic acid, benzoic acid, t-butylbenzoic acid , Monofunctional components such as benzoylbenzoic acid, tricarballylic acid, trimellitic acid, trimesic acid, pyromellitic acid, naphthalenetetracarboxylic acid, gallic acid, trimethylolethane, trimethylolpropane, glycerol, pentaerythritol, sugar ester, etc. One type or two or more types such as a trifunctional or higher polyfunctional component may be used.

In the polyester resin of the present invention, terephthalic acid or its ester-forming derivative preferably accounts for 95 mol% or more of the dicarboxylic acid component, more preferably 98.5 mol% or more, and 100 mol%. It is particularly preferable to occupy Further, ethylene glycol preferably accounts for 95 mol% or more of the diol component, and 97
It is more preferable to occupy at least mol%, particularly preferably at least 98 mol%. As the diol component other than ethylene glycol, the amount of diethylene glycol including the amount added from outside the system and the amount by-produced in the reaction system is
It is preferably 3.0 mol% or less of the diol component,
It is more preferably 0.5 to 2.5 mol%, and 1.0
It is particularly preferably about 2.0 mol%. When the proportion of terephthalic acid or its ester-forming derivative and ethylene glycol is less than the above range, the mechanical strength and heat resistance of the polyester resin tend to be poor, and when the amount of diethylene glycol is less than the above range, the polyester resin is Transparency tends to decrease.

In the polyester resin of the present invention, the number of foreign substance particles having a maximum diameter of 1 μm or more is 20 / 0.01 mm ³ or less, and the number of foreign substance particles is 10 / 0.01 mm ^3. preferably at 0.01 mm ³ or less, five more preferably /0.01Mm ³ or less, more preferably at three or /0.01Mm ³ or less, by two /0.01Mm ³ below It is particularly preferable that the number is 1 / 0.01 mm ³ or less. If the number of the particles of the different substance exceeds the above range, a molding problem such as breakage or yarn breakage during molding into a film or a fiber, and generation of eye blemishes occurs, and a so-called fish eye on the surface of the molded product. The protrusions appear, and it becomes difficult to obtain a film, a fiber, and a molded product such as a bottle having an excellent surface appearance.

Here, it is considered that the heterogeneous substance particles are mainly a substance different from the polyester resin such as a residue such as a polycondensation catalyst, which will be described later, dispersed in the resin in the form of particles, and The number of foreign substance particles having a diameter of 1 μm or more is determined by enlarging a film obtained by melt-molding a polyester resin with an interference microscope and measuring the number of foreign substance particles having a maximum diameter of 1 μm or more with a film area and thickness. Direction,
It is calculated by converting per 0.01 mm ³ .

The polyester resin of the present invention has an intrinsic viscosity ([η]) of 0.55 as a value measured at 30 ° C. in a solution of a mixed solvent of phenol / tetrachloroethane (weight ratio 1/1). It is preferably 0.70 dl / g, more preferably 0.58 to 0.68 dl / g. If the intrinsic viscosity ([η]) is less than the above range, the mechanical strength as a molded product such as a film, a fiber, and a bottle, and transparency will tend to be insufficient. It tends to be difficult to suppress by-products such as acetaldehyde.

The polyester resin of the present invention preferably has a terminal carboxyl group content of 50 equivalents / ton or less. When the amount of the terminal carboxyl group exceeds the above range, the thermal stability in melting is deteriorated, and the resin tends to be thermally decomposed or colored during molding.

The polyester resin of the present invention preferably has a volume resistivity of 1 × 10 ⁶ to 1 × 10 ¹⁰ Ω · cm, and preferably 1 × 10 ⁶ to 1 × 10 ⁹ Ω · cm. More preferably, it is particularly preferably 1 × 10 ^{7 to} 5 × 10 ⁸ Ω · cm. If the volume resistivity is out of the above range, the high-speed moldability of a film or the like tends to decrease.

The polyester resin of the present invention has a color tone of Lab described in Reference 1 of JIS Z8730.
The color coordinate b value of the Hunter color difference formula in the color system is preferably 5 or less, and more preferably 3 or less.
When the b value exceeds the above range, the color tone of the molded product tends to be yellowish.

As described above, the number of particles of different substances is within the above range, the intrinsic viscosity ([η]), the amount of terminal carboxyl groups,
The polyester resin of the present invention in which the volume resistivity and the color coordinate b value satisfy the above-mentioned preferred ranges is a phosphorus compound in which the polycondensation after the esterification reaction or the transesterification reaction between the dicarboxylic acid component and the diol component is a phosphorus compound. The content (P) in the polyester resin as a phosphorus atom derived from the phosphorus compound is preferably 0.1 to 20 ppm, and 2 to 15 pp.
m is more preferable, and 4 to 10 ppm is particularly preferable. When the content (P) as a phosphorus atom is less than the above range, the polycondensation property is good and the particles of different substances are reduced, but the amount of terminal carboxyl groups is increased, the volume resistivity is increased, and the color tone is deteriorated. On the other hand, if the above range is exceeded, problems such as a decrease in polycondensation property and an increase in particles of different substances tend to occur.

Specific examples of the phosphorus compound include orthophosphoric acid, polyphosphoric acid, trimethyl phosphate, triethyl phosphate, tri-n-butyl phosphate, trioctyl phosphate, triphenyl phosphate and triphenyl phosphate. 5 such as cresyl phosphate, tris (triethylene glycol) phosphate, methyl acid phosphate, ethyl acid phosphate, isopropyl acid phosphate, butyl acid phosphate, monobutyl phosphate, dibutyl phosphate, dioctyl phosphate, triethylene glycol acid phosphate, and other phosphoric acid esters -Valent phosphorus compounds, and phosphorous acid, hypophosphorous acid, and trimethyl phosphite, diethyl phosphite, triethyl phosphite, trisdode Luphosphite, trisnonyldecyl phosphite, ethyl diethyl phosphonoacetate, triphenyl phosphite, and other phosphite esters; and lithium, sodium, potassium, and other metal salts, and other trivalent phosphorus compounds. The phosphoric acid ester of the phosphorus compound of 1 is preferable, and trimethyl phosphate and ethyl acid phosphate are particularly preferable.

The polyester resin of the present invention is polycondensed in the presence of a compound of at least one element selected from the group consisting of aluminum, zinc, gallium, germanium and antimony. Are preferred, and the content (S) as a metal atom derived from these compounds is preferably 0.1 to 200 ppm,
More preferably 30 to 150 ppm, 60 to 1
Especially preferred is 00 ppm. When the content (S) as the metal atom is less than the above range, the particles of different substances are reduced, but the polycondensation property is decreased, the terminal carboxyl group amount is increased, and the color tone tends to be deteriorated. On the other hand, if the amount exceeds the above range, problems such as an increase in particles of different substances tend to occur.

In the present invention, the compound of at least one element selected from the group consisting of aluminum, zinc, gallium, germanium, and antimony is preferably an antimony compound, and the antimony atom derived from the antimony compound is preferable. Content (Sb)
Of the phosphorus content (P) as the phosphorus atom (Sb
/ P) is preferably 6 to 45, more preferably 9 to 22.5. If this ratio (Sb / P) is out of the above range, it tends to be difficult to satisfy both the number of different substance particles and the polycondensation property, the amount of terminal carboxyl groups, the volume resistivity, the color tone and the like.

Examples of the aluminum compound, zinc compound, and gallium compound include aluminum, zinc, gallium oxides, hydroxides, alkoxides, carboxylates, carbonates, oxalates, and halides. And the like. Further, as the germanium compound, specifically, for example, germanium dioxide, germanium tetroxide, germanium hydroxide, germanium oxalate, germanium tetraethoxide, germanium tetra-n-butoxide and the like, among them, germanium dioxide preferable. Further, as the antimony compound, specifically, for example, antimony trioxide, antimony pentoxide, antimony acetate, methoxyantimony, triphenylantimony, antimontris ethylene glycolate and the like, among them, among them, antimony trioxide, acetic acid Antimony and antimontris ethylene glycolate are preferable, and antimony trioxide is particularly preferable.

In the polyester resin of the present invention, the polycondensation is at least one selected from the group consisting of metal elements of Group 1A of the periodic table, elements of Group 2A of the periodic table, manganese, iron and cobalt. It is preferably made in the coexistence of a compound of elements, and the content (M) as a metal atom derived from these compounds is preferably 0.1 to 100 ppm, and preferably 10 to 70 ppm. More preferably, it is 20 to 40 ppm, and particularly preferably. When the content (M) of these metal atoms is less than the above range, problems such as a decrease in polycondensation property, an increase in volume specific resistance, and a deterioration in color tone tend to occur. Problems such as an increase in the amount of carboxyl groups tend to occur.

In the present invention, the compound of at least one element selected from the group consisting of metal elements of Group 1A of the periodic table, elements of Group 2A of the periodic table, manganese, iron and cobalt is magnesium. The compound is preferable, and the ratio (Mg / P) of the content (Mg) as the magnesium atom derived from the magnesium compound to the content (P) as the phosphorus atom is preferably 1.5 to 15. It is more preferably 2.5 to 7. If this ratio (Sb / P) is outside the above range,
It tends to be difficult to satisfy both the polycondensation property, the amount of terminal carboxyl groups, the volume resistivity, and the color tone.

Here, a metal element of Group 1A of the periodic table,
Examples of compounds of Group 2A of the periodic table, manganese, iron, and cobalt include oxides, water, such as lithium, sodium, potassium, beryllium, magnesium, calcium, strontium, barium, manganese, iron, and cobalt. Oxides, alkoxides, carboxylates,
Carbonates, oxalates, halides and the like, specifically, for example, lithium acetate, sodium acetate, potassium acetate,
Magnesium oxide, magnesium hydroxide, magnesium alkoxide, magnesium acetate, magnesium carbonate,
Calcium oxide, calcium hydroxide, calcium acetate,
Calcium carbonate, manganese oxide, manganese hydroxide, manganese acetate, manganese benzoate, manganese chloride, manganese methoxide, manganese acetylacetonate, ferric acetate, cobalt formate, cobalt acetate, cobalt naphthenate, cobalt benzoate, cobalt oxalate. , Cobalt carbonate,
Examples thereof include cobalt chloride, cobalt bromide, and cobalt acetylacetonate. Of these, magnesium compounds are preferable, and magnesium acetate is particularly preferable.

Further, the polyester resin of the present invention is preferably one which has been polycondensed in the presence of a compound of a titanium group element of Group 4A of the periodic table, and a metal atom (T ) Content as 0.1-10p
pm is preferable, 0.5 to 6 ppm is more preferable, and 1 to 3 ppm is particularly preferable.
If the content of these metal atoms (M) is less than the above range, problems such as deterioration of polycondensation tend to occur,
On the other hand, when the amount exceeds the above range, problems such as deterioration of color tone tend to occur.

Here, as compounds of titanium group elements of Group 4A of the periodic table, that is, titanium, zirconium and hafnium, oxides, hydroxides, alkoxides, carboxylates, carbonates of these elements, Oxalates, halides and the like can be mentioned. Among them, titanium compounds are preferable, and specific examples of the titanium compound include tetra-n.
-Titanium alkoxides such as propyl titanate, tetra-i-propyl titanate, tetra-n-butyl titanate, tetra-n-butyl titanate tetramer, tetra-t-butyl titanate, tetracyclohexyl titanate, tetraphenyl titanate and tetrabenzyl titanate, titanium Titanium oxide obtained by hydrolysis of alkoxide, titanium-silicon or zirconium composite oxide obtained by hydrolysis of mixture of titanium alkoxide and silicon alkoxide or zirconium alkoxide, titanium acetate, titanium oxalate, potassium titanium oxalate, sodium sodium oxalate. , Potassium titanate, sodium titanate, titanic acid-aluminum hydroxide mixture, titanium chloride, titanium chloride-aluminum chloride mixture, titanium bromide, fluorine Titanium, potassium hexafluorotitanate, cobalt hexafluorotitanate, manganese hexafluorotitanate, ammonium hexafluorotitanate, titanium acetylacetonate, and the like, among which tetra-n-propyl titanate, tetra -Titanium alkoxides such as i-propyl titanate and tetra-n-butyl titanate,
Titanium oxalate and potassium titanium oxalate are preferable, and tetra-
Particularly preferred is n-butyl titanate.

The polyester resin of the present invention undergoes an esterification reaction or transesterification reaction between a dicarboxylic acid component containing terephthalic acid or its ester-forming derivative as a main component and a diol component containing ethylene glycol as a main component. Preferably, in the presence of the phosphorus compound, further in the presence of a compound of at least one element selected from the group consisting of aluminum, zinc, gallium, germanium, and antimony, and / or the periodic table. In the coexistence of a compound of at least one element selected from the group consisting of a metal element of Group 1A, an element of Group 2A of the periodic table, manganese, iron and cobalt, and / or of a group of Group 4A of the periodic table. Obtained by polycondensation in the presence of a compound of at least one element selected from the group consisting of titanium group elements Although the it, its manufacturing method is basically due to the production method of conventional polyester resin.
That is, the dicarboxylic acid component containing terephthalic acid or an ester-forming derivative thereof as a main component and the diol component containing ethylene glycol as a main component were added to a slurry preparation tank together with a copolymerization component used as necessary. And mixed under stirring to form a raw material slurry, which is obtained by carrying out an esterification reaction in an esterification reaction tank under normal pressure to increased pressure and under heating, or an ester exchange reaction in the presence of an ester exchange catalyst. The low molecular weight polyester as an esterification reaction product or a transesterification reaction product is transferred to a polycondensation tank, and melt polycondensation is performed in the presence of the compound under normal pressure, gradually reduced pressure as reduced pressure, and heating. Let

When the transesterification reaction is carried out using an ester-forming derivative of terephthalic acid as the dicarboxylic acid component, usually, a titanium compound, a magnesium compound,
It is necessary to use a transesterification catalyst such as a calcium compound, a manganese compound, or a zinc compound, and it is necessary to use a large amount of the transesterification catalyst, which results in an increase in the number of particles of different substances in the resin. The polyester resin of the present invention is preferably one obtained through an esterification reaction using terephthalic acid as a dicarboxylic acid component.

Here, in the case of the esterification reaction, the raw material slurry is prepared by a carboxylic acid component containing terephthalic acid as a main component, a diol component containing ethylene glycol as a main component, and a copolymerization component used as necessary. And the molar ratio of the diol component to the dicarboxylic acid component is preferably 1.02 to 2.0, more preferably 1.
It is made by mixing as a range of 03 to 1.7.

The esterification reaction is produced by the reaction under the reflux of ethylene glycol using a single esterification reaction tank or a multi-stage reaction apparatus in which a plurality of esterification reaction tanks are connected in series. While removing water and excess ethylene glycol to the outside of the system, the esterification rate (the ratio of those esterified by reacting with the diol component among all the carboxyl groups of the raw material dicarboxylic acid component) is usually 90% or more,
It is preferably performed until it reaches 93% or more. Further, the number average molecular weight of the low molecular weight polyester as an esterification reaction product obtained is preferably from 500 to 5,000.

As the reaction conditions in the esterification reaction, in the case of a plurality of esterification reaction tanks, the reaction temperature in the first stage esterification reaction tank is usually 240 to 270.
C., preferably 245 to 265.degree. C., relative pressure to atmospheric pressure is usually 5 to 300 kPa (0.05 to 3 kg / c).
m ² G), preferably 10 to 200 kPa (0.1 to ² )
kg / cm ² G), the reaction temperature in the final stage is usually 250 to 280 ° C., preferably 255 to 275 ° C., and the relative pressure to atmospheric pressure is usually 0 to 150 kPa (0 to
1.5 kg / cm ² G), preferably 0 to 130 kPa
(0 to 1.3 kg / cm ² G). Incidentally, it is preferable that the esterification rate in each stage is equalized with the increase. When a single esterification reaction tank is used, the reaction conditions in the final stage are adopted.

The esterification reaction may be carried out by adding the compound to be present at the time of polycondensation in the esterification reaction, and, for example, a primary compound such as triethylamine, tri-n-butylamine, benzyldimethylamine or the like can be used. Tertiary amine, tetraethylammonium hydroxide,
By adding a small amount of quaternary ammonium hydroxide such as tetra-n-butylammonium hydroxide or trimethylbenzylammonium hydroxide, or a basic compound such as lithium carbonate, sodium carbonate, potassium carbonate or sodium acetate The by-production of diethylene glycol from ethylene glycol can be suppressed.

Further, in the melt polycondensation, usually, a plurality of melt polycondensation tanks are connected in series, for example, the first stage is a complete mixing type reactor having a stirring blade, the second stage and the third stage. The operation is carried out under reduced pressure while distilling out ethylene glycol as a by-product to the outside of the system by using a multistage reaction device comprising a horizontal plug flow type reactor equipped with a stirring blade.

Regarding the reaction conditions in the melt polycondensation, in the case of a plurality of polycondensation tanks, the reaction temperature in the first stage polycondensation tank is usually 250 to 290 ° C., preferably 260 to 2
80 ° C, absolute pressure is usually 65-1.3 kPa (500
-10 Torr), preferably 26-2 kPa (200
-15 torr), the reaction temperature in the final stage is usually 265 to 300 ° C, preferably 270 to 295 ° C, and the absolute pressure is usually 1.3 to 0.013 kPa (10 to 0.
1 Torr), preferably 0.65 to 0.065 kPa
(5 to 0.5 Torr). As the reaction conditions in the intermediate stage, those intermediate conditions are selected, for example,
In the three-stage reactor, the reaction temperature in the second stage is
Usually 265 to 295 ° C, preferably 270 to 285 ° C,
Absolute pressure is usually 6.5 to 0.13 kPa (50 to 1 T
orr), preferably 4 to 0.26 kPa (30 to 2T
orr).

In the present invention, during polycondensation,
The phosphorus compound, the compound of at least one element selected from the group consisting of aluminum, zinc, gallium, germanium, and antimony, the metal element of Group 1A of the periodic table, the element of Group 2A of the periodic table, manganese, To a reaction system of a compound of at least one element selected from the group consisting of iron and cobalt, and a compound of at least one element selected from the group consisting of titanium group elements of Group 4A of the periodic table. It is preferable to add each compound as a solution of alcohol such as ethylene glycol or water, and the addition timing of each compound is preferably as follows.

The phosphorus compound is preferably added at a stage where the esterification rate is less than 90%. Specifically, it is added to the slurry preparation tank or the first-stage reaction tank in the multistage esterification reaction apparatus. It is preferably added, and particularly preferably added to the slurry adjusting tank.

The aluminum, zinc, gallium,
The compound of at least one element selected from the group consisting of germanium and antimony has an esterification rate of 9
It is preferably added to 0% or more of the esterification reaction product, and specifically, the esterification reaction tank at the final stage in the multi-stage esterification reaction device which has reached the esterification rate or the melt polycondensation tank. Is preferably added to the esterification reaction product of the transfer step to the melt polycondensation tank, and particularly preferably added to the esterification reaction product of the transfer step to the melt polycondensation tank.

Further, the compound of at least one element selected from the group consisting of a metal element of Group 1A of the periodic table, an element of Group 2A of the periodic table, manganese, iron and cobalt,
It is preferable to add to the esterification reaction product having an esterification rate of 90% or more, and specifically, the esterification at the second stage or the final stage in the multistage esterification reaction device which has reached the esterification rate. It is preferably added to the reaction vessel.

The compound of at least one element selected from the group consisting of titanium group elements of Group 4A of the periodic table is added to the esterification reaction product having an esterification rate of 90% or more. Specifically, it is preferably added to the esterification reaction tank at the final stage in the multi-stage esterification reaction device that has reached the esterification rate or to the esterification reaction product at the stage of transfer to the melt polycondensation tank. Is preferred.
The compound is added after the addition of the compound of at least one element selected from the group consisting of the metal elements of Group 1A of the periodic table, the elements of Group 2A of the periodic table, manganese, iron, and cobalt. And is particularly preferably added to the esterification reaction product during the transfer stage to the melt polycondensation tank.

The resin obtained by the melt polycondensation is usually taken out in a strand form from an outlet provided at the bottom of the polycondensation tank, and is cooled with water or after water cooling, and is cut with a cutter into pellets, chips. The polyester resin of the present invention is obtained by forming a granular material such as a shape.

If necessary, for the purpose of further increasing the degree of polymerization or reducing the amount of by-products such as acetaldehyde, the melt-polycondensed granules are treated with, for example, nitrogen,
In an atmosphere of an inert gas such as carbon dioxide or argon, the relative pressure with respect to the atmospheric pressure is usually 100 kPa (1 kg /
cm ² G) or less, preferably 20 kPa (0.2 kg /
cm ² G) or less, usually for about 5 to 30 hours, or as absolute pressure, usually 6.5 to 0.013 kPa
(50-0.1 Torr), preferably 1.3-0.0
Usually 1 under reduced pressure of 65 kPa (10-0.5 Torr)
~ 20 hours, usually 190 ~ 230 ℃, preferably 1
Solid phase polycondensation may be performed by heating at a temperature of 95 to 225 ° C.

At that time, prior to the solid phase polycondensation, in an inert gas atmosphere, a steam atmosphere or a steam-containing inert gas atmosphere, usually at 120 to 200 ° C., preferably at 130 to 190 ° C., 1 It is preferable to crystallize the surface of the resin granules by heating for about 4 minutes to 4 hours.

Further, the resin obtained by the melt polycondensation or the solid phase polycondensation as described above is usually subjected to a water treatment in which it is immersed in warm water of 40 ° C. or higher for 10 minutes or more, or steam or steam of 60 ° C. or higher. A treatment such as steam treatment in which the contained gas is contacted for 30 minutes or more, or treatment with an organic solvent, treatment with an acidic aqueous solution of various mineral acids, organic acids, phosphoric acid, or the like, Group 1A metal, Group 2A The catalyst used for polycondensation can also be deactivated by treatment with an alkaline aqueous solution of a group metal or amine or an organic solvent solution.

The polyester resin of the present invention is formed into a sheet by, for example, extrusion molding, and then thermoformed into a tray, a container or the like, or the sheet is biaxially stretched into a film or the like, or After molding into a preform by injection molding, by stretch blow molding, or by blow molding a parison molded by extrusion molding, it is molded into a bottle, etc., and is particularly useful as a packaging material for food and drink, etc. Become. Further, after being formed into a filament by extrusion molding or the like, it is also useful as a fiber by subjecting it to stretching or spinning.

The polyester resin of the present invention can be molded into the above-mentioned molded product, if necessary, with an antioxidant, an ultraviolet absorber,
Additives that are usually used for polyester resins, such as a light stabilizer, an antistatic agent, a lubricant, an antiblocking agent, an antifogging agent, a nucleating agent, a plasticizer, and a coloring agent, are added and a conventional method is used.

In particular, the polyester resin of the present invention is suitable for use as a biaxially stretched film, and the number of protrusions on the surface of the biaxially stretched film is
It is preferable that the following (1), (2), and (3) are satisfied. (1) The number of protrusions with a height of 0.27 μm or more is 50 / 20c
m ² or less. (2) The number of protrusions with a height of 0.54 μm or more is 10 / 20c
m ² or less. (3) The number of protrusions with a height of 0.81 μm or more is 3/20 cm
² or less.

The height in the above (1) is 0.27 μm.
Or more protrusions number and more preferably at 30/20 cm ² or less, more preferably 20 pieces / 20 cm ² or less, particularly preferably 10/20 cm ² or less. Further, the number of protrusions having a height of 0.54 μm or more in the above (2) is more preferably 5/20 cm ² or less, and the number of protrusions having a height of 0.81 μm or more in the above (3) is 1 It is more preferable that the number is 20/20 cm ² or less.

[0048]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples unless it exceeds the gist.

Example 1 A continuous system comprising a slurry preparation tank, a two-stage esterification reaction tank connected in series thereto, and a three-stage melt polycondensation tank connected in series to a second-stage esterification reaction tank Using a polymerization apparatus, terephthalic acid and ethylene glycol were continuously supplied to the slurry preparation tank in a weight ratio of 865: 485, and an ethylene glycol solution of ethyl acid phosphate was added as a phosphorus atom to the produced polyester resin. (P) of 9 ppm was continuously added, and the mixture was stirred and mixed to prepare a slurry, and the slurry was prepared under a nitrogen atmosphere at 260 ° C. and a relative pressure of 50 kPa (0.5 kg / cm 2). ² G), the first stage esterification reaction tank set to an average residence time of 4 hours, and then 260 ° C. under a nitrogen atmosphere at a relative pressure of 5 kPa (0 ．
(05 kg / cm ² G) and an average residence time of 1.5 hours were continuously transferred to the second stage esterification reaction tank for esterification reaction. At that time, an ethylene glycol solution of magnesium acetate tetrahydrate was continuously supplied through the upper pipe provided in the second stage in an amount such that the content (Mg) as magnesium atom was 30 ppm with respect to the produced polyester resin. Was added. The esterification rates of the first stage and the first stage measured by the methods described below were 85% and 95%, respectively.

<Esterification rate> Samples were deuterated chloroform / hexafluoroisopropanol (weight ratio 7 /
A solution obtained by dissolving 3) in the mixed solvent of 3) at a concentration of 3% by weight was analyzed by a nuclear magnetic resonance apparatus (“JNM-EX27” manufactured by JEOL Ltd.).
0 type "), ¹ H-NMR is measured, each peak is assigned, the terminal carboxyl group amount (A mol / ton of sample) is calculated from the integrated value of the peak, and the terephthalic acid unit of the terephthalic acid unit is calculated by the following formula. The esterification rate (E%) as a ratio of the esterified ester of all the carboxyl groups was calculated. Esterification rate (E) = [1-A / {(1000000/1
92.2) × 2}] × 100

Subsequently, when the esterification reaction product obtained above is transferred to a melt polycondensation tank, an ethylene glycol solution of tetrabutyl titanate is added to the esterification reaction product in the transfer pipe to produce a polyester resin. The content of titanium atoms (Ti) is 2 ppm, and the content of antimony trioxide in ethylene glycol is 90 ppm of antimony atoms (Sb) in the produced polyester resin. At 270 ° C and an absolute pressure of 2.6 kPa (2
The first stage melt polycondensation tank set to 0 Torr), then 278 ° C., absolute pressure 0.5 kPa (4 Torr)
2nd stage melt polycondensation tank set to
The polyester resin obtained by continuous transfer to the third-stage melt polycondensation tank set to 0 ° C. and an absolute pressure of 0.3 kPa (2 Torr) has an intrinsic viscosity ([η]) of 0.65 dl.
/ G to adjust the residence time in each polycondensation tank to perform melt polycondensation, draw out in strands from the outlet provided at the bottom of the polycondensation tank, cool with water, then cut with a cutter to form chips A granular polyester resin was produced.

With respect to the obtained polyester resin, the content of diethylene glycol, the content of metal atoms, the number of particles of different substances, the intrinsic viscosity, the amount of terminal carboxyl groups, the volume resistivity and the color tone were measured by the following methods, and the results were obtained. The results are shown in Table 1.

<Diethylene glycol content> A solution prepared by dissolving a resin sample in a mixed solvent of deuterated chloroform / hexafluoroisopropanol (weight ratio 7/3) at a concentration of 3% by weight was analyzed by a nuclear magnetic resonance apparatus (manufactured by JEOL Ltd.). "JNM-EX270 type") was used to measure ¹ H-NMR to assign each peak, and the mol% of diethylene glycol relative to the total diol component was calculated from the integrated value of the peak.

<Metal Atom Content> 2.5 g of resin sample
After ashing with hydrogen peroxide in the presence of sulfuric acid by a conventional method and completely decomposing, the volume was adjusted to 50 ml with distilled water. A plasma emission spectrophotometer (IC manufactured by JOBIN YVON
P-AES "JY46P type") and quantified, and converted into ppm amount in the polyester resin.

<Number of Particles of Different Substances> 10 kg of resin sample
Crystallize and dry in a hot-air dryer at 180 ° C for 2 hours to reduce the water content to 100 ppm or less, and then incorporate a metal fiber sintered filter (95% cut filtration accuracy 15 µm) in a 40 mm diameter uniaxial extruder. , A tubular film molding machine equipped with a 4-mm spiral annular die having a diameter of 80 mm, melt-extruded at a resin temperature of 285 ° C. and an extrusion rate of 8 kg / hour, cooled by a cooling ring having a diameter of 60 mm to form a tubular film, 210 μm, folding width 10 cm
To obtain a tubular film of. The inner surface of the tubular film was used as a spectroscopic sample, and a phase-contrast microscope (“OPTIPHOT XF-Ph type” manufactured by Nikon Corporation, with an objective lens of 4) was used.
CCD camera is attached to the trinocular tube (using 0X), the magnification on the display is 1,000 times, and the field of view range is 0.1.
23 mm × 0.114 mm, and an image processing device (“SPICCA0-II manufactured by Japan Avionics Co., Ltd.
Type ”) as a grayscale image. Then, after checking the film thickness range by focusing on the front and back surfaces of the film, the image processing device captures the image while performing focus scanning from the front surface to the back surface in the accumulation input mode of the grayscale image, and is recognized by the image processing device. The maximum value of the linear distance between two points on the circumference of the particle is defined as the maximum diameter, and the operation of counting the number of particles having the maximum diameter of 1 μm or more is repeated three times in different fields of view, and the average value of the numbers is set to 0. It was converted per film volume of 01 mm ³ .

<Intrinsic viscosity> Freeze-pulverized resin sample 0.2
5 g of phenol / tetrachloroethane (weight ratio 1 /
In the mixed solvent of 1), the concentration (c) was 1.0 g / dl.
And melt at 110 ° C for 30 minutes, then use Ubbelohde type
Relative viscosity (η) with the stock solution at 30 ° C using a capillary viscous tube
_rel) Is measured and the relative viscosity (η_rel) -1
Specific viscosity (η _sp) And the concentration (c) (η_sp/ C)
Therefore, similarly, the concentration (c) is 0.5 g / dl, 0.2 g / d
The ratio of 1 and 0.1 g / dl
(Η_sp/ C), and the concentration (c) is set to 0 from these values.
The ratio (η_sp/ C) is the intrinsic viscosity [η] (d
1 / g).

<Terminal carboxyl group amount> After crushing the chips, the chips were dried at 140 ° C. for 15 minutes with a hot air dryer, and 0.1 g was accurately weighed from a sample cooled to room temperature in a desiccator and collected in a test tube. Then, 3 ml of benzyl alcohol was added and dissolved at 195 ° C. for 3 minutes while blowing dry nitrogen gas, and then 5 ml of chloroform was gradually added and cooled to room temperature. 1 to 2 drops of phenol red indicator was added to this solution, and the solution was titrated with a benzyl alcohol solution of 0.1N caustic soda while stirring while blowing dry nitrogen gas, and the reaction was terminated when the color changed from yellow to red.
Further, as a blank, the same operation was performed without the polyester resin sample, and the acid value was calculated by the following formula.

Acid value (equivalent / ton) = (AB) × 0.1 × f / W [where A is the amount of a 0.1 N caustic soda benzyl alcohol solution (μl) required for titration, B is the amount of a 0.1N caustic soda solution in benzyl alcohol (μl) required for titration with a blank, W is the amount of a polyester resin sample (g), and f is the amount of a 0.1N caustic soda solution in benzyl alcohol. It is a titer. ]

The titer (f) of a 0.1N caustic soda solution in benzyl alcohol was measured by adding 5 ml of methanol to a test tube.
1 to 2 drops of an ethanol solution of phenol red as an indicator were added and titrated with 0.4 ml of a 0.1 N benzyl alcohol solution of caustic soda until the color change point, and then a 0.1 N hydrochloric acid aqueous solution having a known titer was added. As a standard solution, 0.2 ml was sampled and added, and the solution was titrated again with a 0.1N caustic soda solution in benzyl alcohol until the color change point. (The above operation was performed under blowing of dry nitrogen gas.) The titer (f) was calculated by the following formula. Titer (f) = Titer of 0.1N hydrochloric acid aqueous solution × Amount of 0.1N hydrochloric acid aqueous solution (μl) /0.1 N caustic soda benzyl alcohol solution titer (μl)

<Volume resistivity> 15 g of a resin sample was put into a test tube with a branch having an inner diameter of 20 mm and a length of 180 mm, the inside of the tube was sufficiently replaced with nitrogen, and the tube was immersed in an oil bath at 160 ° C. to vacuum pump the inside of the tube. After vacuum drying at 1 Torr or less for 4 hours, the temperature of the oil bath was raised to 285 ° C. to melt the resin sample, and nitrogen recompression and decompression were repeated to remove mixed bubbles. ^Two stainless steel electrodes with an area of 1 cm ² were inserted in this melt in parallel at intervals of 5 mm (non-opposing back surfaces were covered with an insulator), and after the temperature was stabilized, a resistance meter (manufactured by Hewlett-Packard Co., Ltd. "MODEL HP4329A") DC voltage 100V
Is applied, and the resistance value is then changed to the volume specific resistance (Ω · c
m).

<Color Tone> A resin sample was filled in a cylindrical powder color measuring cell having an inner diameter of 36 mm and a depth of 15 mm, and a colorimetric color difference meter (“ND-300A” manufactured by Nippon Denshoku Industries Co., Ltd.) was used. ,
The color coordinate b value of the Hunter color difference formula in the Lab color system described in Reference 1 of JIS Z8730 was obtained as a simple average value of values measured at four points by rotating the measurement cell by 90 degrees by the reflection method.

On the other hand, an unstretched film was formed from the obtained polyester resin by tubular molding in the same manner as in the measurement of the number of particles of different substances, and subsequently, a biaxial stretching machine (manufactured by TM Long Co.) was used. ), The unstretched film was preheated at 92 ° C. for 2 minutes and then 20,000% /
A biaxially stretched film is obtained by simultaneously biaxially stretching at a stretching ratio of 4.0 times in the longitudinal direction and 3.5 times in the lateral direction at a stretching speed of 1 minute, and then heat-setting at 92 ° C. for 1 minute after stretching. Molded.

With respect to the obtained biaxially stretched film, the number of protrusions on the film surface was observed by the method described below, and the results are shown in Table 1. <Number of protrusions on the surface of the biaxially stretched film> The biaxially stretched film is stretched on a square metal frame made of SUS, aluminum is vapor-deposited in a vacuum vapor deposition machine, and a 2.0 cm x 2.5 cm frame is randomly marked on the surface. Then, the number of coarse projections within the area was observed by a two-beam microscope using a halogen lamp white light with a G filter as a light source. Coarse protrusions are observed as contour lines in which interference fringes are closed, and the number of contour lines increases as the protrusion height increases. In the present invention, the protrusion height is 0.27 μm, 0.54 μm, and 0.81 μm.
The number of protrusions was counted in the following categories according to the number of each contour line of, and converted into a film area of 20 cm ² . (1) The number of protrusions having a height of 0.27 μm or more with one or more contour lines. (2) The number of projections having a contour line number of 2 or more and a height of 0.54 μm or more. (3) The number of projections having a height of 0.81 μm or more with three or more contour lines.

Separately, the dried polyester resin chips were melt-spun by the following method, and the presence or absence of eye crevices at the die exit was evaluated. <Presence or absence of eye blemishes> Presence or absence of eye dies in die after continuous molding at a spinning temperature of 295 ° C. for 48 hours with an extruder type spinning machine equipped with a die having a large number of round holes with a diameter of 0.6 mm. Was visually observed.

Examples 2 to 16 The same as in Example 1 except that the addition amounts of ethyl acid phosphate, magnesium acetate tetrahydrate, tetrabutyl titanate, and antimony trioxide were changed as shown in Table 1. A polyester resin chip was manufactured and evaluated in the same manner, and the results are shown in Table 1.

Example 17 A polyester resin chip was produced in the same manner as in Example 1 except that orthophosphoric acid was used in place of ethyl acid phosphate, and the same evaluation was performed. The results are shown in Table 1.

Comparative Example 1 As the esterification reaction device, a first esterification reaction tank equipped with a stirrer, a partial condenser, a raw material charging port, and a product outlet port, and the reaction tank were divided into two parts. A three-stage complete mixing tank type continuous reaction device comprising a second esterification reaction tank equipped with a stirrer, a partial condenser, a raw material charging port, and a product outlet port in each of the first tank and the second tank Use, first
The molar ratio of ethylene glycol to terephthalic acid was 1.
While continuously supplying the slurry adjusted to 7, the content (Mg) as magnesium atom of the ethylene glycol solution of magnesium acetate tetrahydrate becomes 20 ppm with respect to the produced polyester resin from another charging port. The amount of the reaction product is continuously added, and the reaction product is transferred to the first tank of the second esterification reaction tank at an atmospheric pressure of 255 ° C. and an average residence time of 4 hours. Transfer from the second tank to the second tank by overflow method,
In the first tank, a solution of orthophosphoric acid in ethylene glycol was added as a phosphorus atom (P) in the produced polyester resin.
Of 5 ppm, and further added to the second tank in an amount of 19 ppm, continuously added at atmospheric pressure and 260 ° C., respectively.
The esterification reaction was carried out at an average residence time of 2.5 hours.

Subsequently, the obtained esterification reaction product was transferred to a melt polycondensation tank equipped with a two-stage polycondensation tank equipped with a stirrer, a partial condenser, a raw material charging port, and a product outlet port. At that time, an ethylene glycol solution of antimony trioxide was added to the esterification reaction product in the transfer pipe in an amount such that the content (Sb) as an antimony atom in the produced polyester resin was 80 ppm, A solution of butyl titanate in ethylene glycol was added as a titanium atom (T
i) becomes 3ppm, while continuously adding 27
Melt polycondensation was performed at 0 ° C. under reduced pressure for a residence time of 3 hours and 19 minutes, and the mixture was extracted in a strand form from an outlet provided at the bottom of the polycondensation tank, cooled with water, and then cut with a cutter to obtain chip-like granular bodies. A polyester resin was produced. The obtained polyester resin chips were evaluated in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 2 Tetrabutyl titanate was not added, and magnesium acetate tetrahydrate and antimony trioxide were mixed as a mixture of the two to form the ester in the transfer pipe of the esterification reaction product to the melt polycondensation tank. A polyester resin chip was produced in the same manner as in Example 1, except that the addition amount was changed to that shown in Table 1 including the addition of ethyl acid phosphate. The evaluation was performed and the results are shown in Table 1.

Comparative Example 3 100 parts by weight of dimethyl terephthalate and 70 parts by weight of ethylene glycol, calcium acetate monohydrate and magnesium acetate tetrahydrate as transesterification catalysts were added as calcium atoms to the produced polyester resin. The content (Ca) was 67 ppm and the content as magnesium atom (Mg) was 47 ppm, and 20 minutes after the start of methanol distillation, antimony trioxide was added as an antimony atom to the produced polyester resin. Is added in an amount such that the content (Sb) of the compound (Sb) is 47 ppm to cause a transesterification reaction, and trimethyl phosphate is further added to the resulting polyester resin in an amount such that the content (P) as a phosphorus atom is 40 ppm. The exchange reaction was substantially terminated. Subsequently, tetrabutyl titanate was added to the resulting polyester resin in an amount such that the content of titanium atoms (Ti) was 5 ppm, and melt polycondensation was performed for 3 hours and 3 minutes under high temperature and reduced pressure according to a conventional method. A polyester resin was produced from the extraction port provided at the bottom of the condensation tank in the form of a strand, cooled with water, and then cut with a cutter to obtain a chip-shaped granular body. The obtained polyester resin chips were evaluated in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 4 254 parts by weight of bis (β-hydroxyethyl) terephthalate and 83 parts by weight of terephthalic acid were placed in a polymerization vessel having a rectification column and stirred at 250 ° C. while flowing a slight amount of nitrogen.
Up to the temperature, during which ethylene glycol is refluxed,
Only the generated water was distilled out of the system. Calculated from the amount of distilled water, when the transesterification rate reached 80%, a mixture of antimony trioxide and tetrabutyl titanate, magnesium acetate tetrahydrate, and trimethyl phosphate were each added as an ethylene glycol solution, With respect to the produced polyester resin, the content (Sb) as an antimony atom is 100 ppm, the content (Ti) as a titanium atom is 1 ppm, the content (Mg) as a magnesium atom is 65 ppm, and the content as a phosphorus atom ( P) is added in an amount of 50 ppm, the pressure is gradually reduced while continuing heating and stirring, the temperature in the can is reduced to 5 Torr or less over about 1 hour, and the temperature is raised to 285 ° C. over 5 hours and 20 minutes. Melt polycondensate, draw out in a strand from the outlet provided at the bottom of the can, cool with water, and then cut with a cutter. Was prepared polyester resin was chip-shaped granules with. The obtained polyester resin chips were evaluated in the same manner as in Example 1, and the results are shown in Table 1.

[0072]

[Table 1]

[0073]

[Table 2]

[0074]

EFFECTS OF THE INVENTION According to the present invention, a film or fiber having excellent surface appearance, in which molding problems such as breakage and yarn breakage in the formation of a film or fiber, and the occurrence of eye blemishes are suppressed, It is also possible to provide a polyester resin capable of obtaining a molded article such as a bottle, and a film or fiber made of the polyester resin.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yutaka Yagi             1 Toho-cho, Yokkaichi-shi, Mie Mitsubishi Chemical Corporation             Inside the company (72) Inventor Norio Kobe             1 Toho-cho, Yokkaichi-shi, Mie Mitsubishi Chemical Corporation             Inside the company (72) Inventor Hiroshi Niwa             1 Toho-cho, Yokkaichi-shi, Mie Mitsubishi Chemical Corporation             Inside the company (72) Inventor Masahiro Nukui             1 Toho-cho, Yokkaichi-shi, Mie Mitsubishi Chemical Corporation             Inside the company F-term (reference) 4F071 AA44 AA80 AA88 AB06 AB09                       AB10 AC15 AE21 AF27 AF29                       AF55 AH05 AH19 BA01 BB06                       BB08 BC01 BC08 BC14                 4J029 AA03 AB01 AB04 AC01 AD01                       AE01 AE02 AE03 BA01 BA02                       BA03 BB04B BD03A BF08                       BH02 CA02 CA06 CB04A                       CB05A CB05B CB10A CC05A                       CF06 CF08 DB02 HA01 HB01                       HB02 HB03A JA011 JA251                       JC411 JC481 JC581 JF181                       JF221 JF231 JF361 JF471                       KE02

Claims (12)

[Claims] 1. A dicarboxylic acid component containing terephthalic acid or an ester-forming derivative thereof as a main component and a diol component containing ethylene glycol as a main component are polycondensed through an esterification reaction or a transesterification reaction. A polyester resin, wherein the number of particles of different substances having a maximum diameter of 1 μm or more is 20 particles / 0.01 mm ³ or less. 2. The polyester resin according to claim 1, which is polycondensed in the presence of a phosphorus compound and has a content (P) as a phosphorus atom derived from the phosphorus compound of 0.1 to 20 ppm. . 3. A compound which is polycondensed in the presence of a compound of at least one element selected from the group consisting of aluminum, zinc, gallium, germanium, and antimony, and which serves as a metal atom derived from these compounds. The polyester resin according to claim 2, having a content (S) of 0.1 to 200 ppm. 4. A compound of at least one element selected from the group consisting of aluminum, zinc, gallium, germanium, and antimony is an antimony compound,
The polyester resin according to claim 3, wherein the ratio (Sb / P) of the content (Sb) as an antimony atom derived from the antimony compound to the content (P) as a phosphorus atom is 6 to 45. 5. A metal element belonging to Group 1A of the periodic table and a second group of the periodic table
It is polycondensed in the coexistence of a compound of at least one element selected from the group consisting of Group A elements, manganese, iron, and cobalt, and its content as a metal atom derived from these compounds ( The polyester resin according to any one of claims 2 to 4, wherein M) is 0.1 to 100 ppm. 6. A metal element belonging to Group 1A of the periodic table, a second element of the periodic table
The compound of at least one element selected from the group consisting of Group A elements, manganese, iron, and cobalt is a magnesium compound, and the phosphorus atom having a content (Mg) as a magnesium atom derived from the magnesium compound. Ratio (Mg / P) to the content (P) as
The polyester resin according to claim 5, which is 15. 7. Polycondensation in the presence of a compound of at least one element selected from the group consisting of titanium group elements of Group 4A of the Periodic Table, as a metal atom derived from these compounds. Content (T) is 0.1-10ppm
The polyester resin according to any one of claims 2 to 6, which is 8. A compound of at least one element selected from the group consisting of titanium group elements of Group 4A of the periodic table is a titanium compound, and the content (Ti) as a titanium atom derived from the titanium compound is The polyester resin according to claim 7, which is 0.5 to 6 ppm. 9. The phosphorous compound is a phosphoric acid ester.
9. The polyester resin according to any one of 8 to 8. 10. An intrinsic viscosity of 0.55 to 0.70 dl /
The polyester resin according to any one of claims 1 to 9, wherein g, the amount of terminal carboxyl groups are 50 equivalents / ton or less, and the volume resistivity is 1 × 10 ⁶ to 1 × 10 ¹⁰ Ω · cm. 11. The number of protrusions having a height of 0.27 μm or more on the surface of the biaxially stretched film is
The following (1), (2), and (3) are satisfied:
10. The polyester resin according to 10. (1) The number of protrusions with a height of 0.27 μm or more is 50 / 20c
m ² or less. (2) The number of protrusions with a height of 0.54 μm or more is 10 / 20c
m ² or less. (3) The number of protrusions with a height of 0.81 μm or more is 3/20 cm
² or less. 12. A film made of the polyester resin according to claim 1.